Percutaneous left ventricular assist device as a short-term mechanical circulatory support before heart transplantation in patients with high pre-transplant pulmonary hypertension (series of clinical cases)

Abstract

Federation In certain categories of patients with end-stage heart failure (HF), short-term mechanical circulatory support (MSC) is successfully used as a mechanical «bridge» to heart transplantation (HTx). In predominantly left-ventricular (LV) dysfunction, the use of isolated coronary artery bypass, especially amidst high pulmonary hypertension (PH), seems to be a more physiological method of short-term MSC.Objective: to present the results of a series of clinical cases of the use of percutaneous left ventricular assist device (pLVAD) before HTx in potential recipients with predominantly LV dysfunction and concomitant high PH.Materials and methods. Three potential heart recipients with predominantly left-sided HF and high pre-transplant PH (pulmonary vascular resistance, PVR, 4.7–6.6 Wood units) who required MSC due to progression of hemodynamic disorders were included in the study. A standard venous extracorporeal membrane oxygenation (ECMO) cannula (26 F) was used for percutaneous left atrial-femoral artery (LA–FA) bypass. The cannula was passed from the transfemoral route through the interatrial septum into the left atrial cavity. A paracorporeal centrifugal pump provided blood injection through a standard arterial ECMO cannula (15 F).Results. pLVAD unloaded the left ventricle effectively (PCWP reduced from 27–32 to 15–20 mmHg), reduced pre-transplant PH (mean pulmonary artery pressure (mPAP) reduced from 45–53 to 28–33 mmHg) and improved systemic hemodynamics (cardiac index (CI) increased from 1.8–1.9 to 2.1–2.6 l/min/m2 and mean arterial pressure (mAP) from 56–59 to 70–75 mmHg). All these created the prerequisites for subsequent successful HTx. Against the background of pLVAD, transpulmonary pressure gradient (TPG) decreased from 15–25 to 13–15 mmHg, and PVR decreased from 4.7–6.6 to 2.7–3.4 Wood units. pLVAD flow rate was 2.9–3.8 L/min or 1.38–1.83 L/min/m2 at 4700–7100 rpm. pLVAD duration ranged from 4 (n = 1) to 7 (n = 2) days. All patients underwent successful HTx.Conclusion. pLVAD is a highly effective method of short-term MSC in potential recipients with predominantly LV dysfunction and concomitant high PH, leading to rapid regression of the dysfunction against the background of left ventricular unloading. This short-term MSC technique can be successfully realized using standard ECMO cannulas and centrifugal pumps of any modification, without requiring additional special equipment.

Keywords

• heart transplantation
• mechanical circulatory support
• pulmonary hypertension